JPS6350158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a roll paper cutting method for a roll paper feeding device such as a copying machine or an electrostatic recording device.

Conventionally, in roll paper feeding devices such as copying machines, when cutting roll paper, a stop signal for the roll paper feeding means and a drive start signal for the cutter are generated at the same time, and the cutter is activated at the same time as the roll paper feeding is stopped. It was driving. In this case, in order to avoid image disturbance due to so-called cut-shock when cutting the roll paper, the feeding speed of the roll paper is set to be sufficiently faster than the linear speed of the image carrier (for example, a photoreceptor drum), and the difference in speed is The paper is slackened to prevent the paper from cutting, or the conveyance path between the cutter and the image carrier is made long so that the rolled paper does not hang on the image carrier when the cutter is operated.

However, although a configuration that increases the feeding speed of roll paper is effective when cutting short lengths of paper, when feeding long size paper such as paper for computer output, the slack may be reduced. As the condition progresses, defects that cause jamming, wrinkles, and folded ears develop. On the other hand, one of the advantages of using roll paper is that it is possible to make copies of long-sized copy paper, so the above-mentioned disadvantages will reduce the advantages of using roll paper.

In addition, lengthening the conveyance path increases the size of the equipment,
This is undesirable because it causes an increase in jams, and it also has the disadvantage of increasing image position deviation.

Purpose The present invention solves the above-mentioned drawbacks, and provides a roll paper cutting method for a roll paper feeder that prevents image disturbance when cutting roll paper and reduces jams, wrinkles, and folded edges of roll paper. The purpose is to

Configuration To achieve this object, the present invention has a cutter that has an intermittent drive device and cuts the roll paper in response to a cut signal, and a cutter that feeds the roll paper to the cutter and has an intermittent drive device. a first feeding device having a first feeding device; and a second feeding device that feeds the roll paper fed via the cutter by the first feeding device further forward.
feeding means, the roll paper is fed under tension between the first feeding means and the second feeding means, and the rolled paper is cut by the cutter during feeding. The roll paper cutting method in the apparatus is characterized in that after the cutter starts operating in response to a cut signal, the drive of the first feeding means is stopped at the same time or immediately before the cutter touches the roll paper for actual cutting. That is.

The present invention will be explained below using examples. Note that an electrophotographic copying machine employing a roll paper feeding device will be described below as an example.

First, FIG. 1 shows an example of a roll paper feeder to which the present invention is applied. The roll paper 1 is pulled out from the roll 2 on which the roll paper 1 is wound by a first feeding means configured as a first feeding roller pair 3 consisting of a first drive roller 4 and a first driven roller 5, and is pulled out by a cutter 9. Through this, a second feeding means is reached, which is configured as a second feeding roller pair 6 consisting of a second driving roller 7 and a second driven roller 8 . Thereafter, the paper is continuously fed, passes through the third feeding roller pair 12, and reaches an image carrier configured as a photosensitive drum 17. A toner image is formed on the photosensitive drum 17 by an image forming means (not shown), and the fed roll paper 1 is superimposed on the toner image, and the toner image is transferred to the roll paper by the transfer means 16. Ru.

Now, the roll paper 1 that has been fed out by a predetermined amount is cut into a predetermined length by the cutter 9. In the example shown in FIG. 1, the cutter 9 has a rotary blade 10 and a fixed blade 1.
1, which cuts the roll paper 1 by rotating the rotary blade 10, but other types of cutters may of course be used. In a conventional roll paper feeder, the process until the roll paper 1 is cut by a cut signal is as follows.

That is, simultaneously with the cut signal, the paper feeding of the first feeding roller pair 3 is stopped, and at the same time, the cutter 9 starts operating. However, even when the cutter 9 starts operating, cutting does not begin immediately, and requires time to rise. The rise time t ₀ is the sum of the delay time t ₁ from when the cut signal is generated until the rotary blade 10 starts rotating and the time t ₂ from when the rotary blade 10 starts rotating until the start of cutting (t ₀ = t ₁ + t ₂ ). Said time t ₁
is the operating time of the drive means necessary for operating the rotary blade 10, such as a clutch or solenoid, and the time _t2 is the time when the roll paper 1 passes between the rotary blade 10 and the fixed blade 11, so both blades are operated. It is necessary to leave a gap between 10 and 11, and this is the time required for the rotary blade to move by this amount.

Furthermore, a time _t3 from when the rotary blade 10 starts cutting to when it finishes cutting is also required. That is, in the case of cutting the roll paper 1, as in the case of general scissors or cutters, the cutting generally starts from one side of the roll paper 1, as shown by hatching in FIG. 2 to indicate the cutting blade.
Cutting is completed by rotating the rotary blade 10 at a constant angle, and the actual cutting time required for this is _t3 .

Conventionally, the paper feeding operation of the first feeding roller pair 3 is stopped for cutting during the above-mentioned rise time t ₀ and actual cutting time t ₃ (t ₀ +t ₃ =t ₁ +t ₂ +t 3 ₎ . Now, if the linear velocity of the photosensitive drum 17 is v, then when cutting the roll paper 1, the slack of the roll paper 1 between the cutter 9 and the transfer means 16 requires v×(t ₁ +t ₂ +t ₃ ). , if this slack is shorter than v x (t ₁ + t ₂ + t ₃ ), paper feeding will also stop at the image transfer position due to the stop of the paper feeding operation in the first feeding roller pair when cutting the roll paper. When a situation arises, a so-called cut-shock phenomenon occurs in which the image is distorted, as shown by D in FIG. (Note that E indicates the distance between the cutting means and the transfer means). Therefore, in order to prevent image disturbance when cutting roll paper, cutter 9 and transfer means 1
6 (substantially between the first feeding roller pair 3 and the second feeding roller pair 3)
Since the roll paper 1 is under tension between the feeding roller pair 6 and the transfer means 16 for accurate cutting, v×(t ₁ + t ₂ + t ₃ ) or more of the roll paper is required. Conventionally, this slack has been generally obtained by making the paper feed speed of the roll paper faster than the linear velocity of the photoreceptor drum 17, as described above, and this slack is absorbed by the slack absorbing guide plate 15. However, when it is desired to copy onto long-sized copy paper, the slack absorbing guide plate 15 cannot absorb the slack, causing jams and the like, as described above. Note that the second feeding roller pair 6
continues to rotate and feed paper during copying, including when cutting is being performed.

Next, one embodiment of the present invention will be described.

In this embodiment, the cut signal applied to the cutter 9 is simultaneously applied to a delay timer device (not shown), and the rise time t ₀ (=
The stop signal for the first feed roller pair 3 is generated with a delay equal to or slightly shorter than t ₁ +t ₂ ). As a result, after the cutter 9 starts operating, the feeding operation of the roll paper 1 by the first feed roller pair 3 is stopped immediately before the cutter 9 starts cutting the roll paper. In this case, it would be ideal to make the delay time exactly equal to the rise time t ₀ (=t ₁ + t ₂ ) so that the paper is cut at the same time as the first feed roller pair stops. However, in reality, the time t ₁ +t ₂ varies to some extent, so it is practical to make the delay time slightly shorter than t ₁ +t ₂ as described above. The relationship between these signals is illustrated in FIG. 4.

To explain the above-mentioned configuration more specifically, the fifth
As shown in the figure, a cutting signal is first applied to the cutter 9, and the cutter 9 starts operating. Thereafter, just before the end of the rise time t ₀ (=t ₁ +t ₂ ), that is, just before the cutter 9 starts cutting the roll paper 1, the rotation of the first feed roller pair 3 is stopped, and the roll paper 1 is fed by the roller pair 3. The sending operation is stopped. This rise time t ₀
During this period, the cutter 9 does not apply any force to the roll paper 1, and therefore, no problem occurs even if the first feeding roller pair 3 is driven intermittently during this period. Further, while the cutter 9 is cutting the roll paper 1, that is, during the actual cutting time _t3 , the feeding of the roll paper 1 by the first feed roller pair 3 is stopped, so the first feed roller pair 3 and the second feed roller pair The roll paper 1 is maintained under tension between the feed roller pair 6, ensuring accurate cutting.

In addition, the feeding stop period of the roll paper 1 is almost only during the actual cutting time t ₃ , and during the slack of v × (t ₁ + t ₂ + t ₃ ), which was conventionally required to prevent image disturbance, v × ( The length corresponding to t ₁ + t ₂ ) is normally fed by the first, second and third feeding roller pairs 3, 6 and 12, and immediately before the first feeding roller pair 3 stops the roll paper. If you create slack in V・T ₃ in advance, the image will not be disturbed by the cutting shot.
Therefore, the amount of slack needs to be extremely short, and even when copying long-sized paper, this slack can be absorbed by the slack absorbing guide 15 without any problem.
It is possible to suppress the occurrence of paper jams, wrinkles, edge folds, etc.

According to one measurement result _{, in} the roll paper feeding device _shown in FIG _.
sec, t ₂ ≒ 25 m sec, t ₃ ≒ 20 m sec (However, this is the value when the width of roll paper 1 is 297 mm, and the times t ₁ , t ₂ , t ₃ are In general, if the width of the roll paper 1 becomes wider, t ₂ will become shorter and t ₃ will become longer). As is clear from this measurement result, t ₁ + t ₂ occupies about 80% of t ₁ + t ₂ + t ₃ ,
In this case, the amount of slack in the paper required to prevent the image from being disturbed by the shock during cutting when this embodiment is applied is only 20% of the conventional length. Therefore, this amount of slack can be easily absorbed, and jamming, wrinkles, and folded edges are less likely to occur.

In the above explanation, the first feeding roller pair 3
The explanation has been made assuming that the timing at which the feed of the roll paper 1 is stopped is mainly just before the cutter 9 starts cutting the roll paper 1, but now the delay time of the above-mentioned paper feed stop signal for the roll paper 1 from the cut signal is defined as _t4 . Then, the effect is exerted within the range of time t ₄ that satisfies the formula O<t ₄ <(t ₁ +t ₂ ), and the effect becomes larger as t ₄ approaches (t ₁ +t ₂ ).

In the above embodiment, the timer device is used to set the feeding stop timing to be at the same time as or immediately before the actual cutting, which is later than the cutter drive start timing. Other configurations may also be adopted as appropriate. A and b in FIG. 6 show specific examples thereof.

In FIG. 6a, the cam 18 is fixed to the rotating shaft of the rotary blade 10, and the cam 18 is rotated by the rotation of the rotary blade 10.
The switch 19 is actuated by the rotation of the roller 8, and the output of the switch 19 is used as a stop signal for the first pair of feeding rollers 3. In this case, the cam 1 is
It is a matter of course that the protrusions 8, switches 19, etc. are arranged.

In addition, in the case of the embodiment shown in FIG. 6a, the rotary blade 10
Even if the rise time t ₀ (=t ₁ + t ₂ ) fluctuates, for example _, because the paper feed stop signal is obtained by the rotation of the This is particularly advantageous since the feeding of the roll paper 1 can be accurately stopped.

In addition, as shown in FIG. 6b, a rotary encoder 20 is fixed to the shaft of the rotary blade 10 in place of the cam 18, and the output pulses of the rotary encoder 20 are counted and the signal when a predetermined number of pulses are output is sent to the first feed. It may also be used as a stop signal for the roller pair 3.

Effects As explained above, according to the present invention, the timing to stop feeding the roll paper is set to be approximately at the same time as the start of the actual cutting time _t3 , or just before that, and the roll paper can be cut as required to prevent image disturbance due to cutting of the roll paper. It is possible to reduce the amount of slack and prevent image distortion. It is also possible to reduce jams, wrinkles, folded edges, etc. of roll paper.

Furthermore, although the explanation has been made using three pairs of feeding rollers as the feeding means, the same applies to other feeding means such as belts, and other rollers such as electrostatic recording devices of facsimile machines as well as copying machines can be used. It can also be applied to paper feeding devices.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a roll feeding device to which the present invention is applied, FIG. 2 is an explanatory diagram of a cutter,
FIG. 3 is an explanatory diagram illustrating image disturbance caused by a shock when cutting roll paper, FIGS. 4 and 5 are explanatory diagrams illustrating the operation of an embodiment of the present invention, and FIG.
Figures a and b are illustrations of other embodiments of the invention. 1... Roll paper, 3... First feeding means, 6...
Second feeding means, 9... cutter.

Claims (1)

[Scope of Claims] 1. A cutter that has an intermittent drive device and cuts the roll paper in response to a cut signal, and a first feeding means that feeds the roll paper to the cutter and has an intermittent drive device. and a second feeding means for feeding the roll paper fed via the cutter by the first feeding means further forward, the first feeding means and the second feeding means having a crotch. In a method for cutting roll paper in a roll paper feeding device in which a roll paper is fed under tension and the cutter cuts the roll paper during feeding, the cutter is The roll paper cutting method characterized in that the driving of the first feeding means is stopped at the same time or immediately before the paper contacts the roll paper for actual cutting.